The final debate between US President Donald Trump and Democratic rival Joe Biden will feature a mute button to allow each candidate to speak uninterrupted, organisers said on Monday, looking to avoid the disruptions that marred the first matchup.

The Trump campaign voiced objections to the change — made after the president repeatedly talked over both Biden and the moderator at last month’s debate in violation of its agreed-upon rules — but said the Republican would still take part in the Thursday night event, one of his last chances to reach a large prime-time audience before voting ends on November 3.

The Presidential Commission on Debates said each candidate’s microphone at the debate in Nashville, Tennessee, would be silenced to allow the other to make two minutes of opening remarks at the beginning of each 15-minute segment of the debate. Both microphones will be turned on to allow a back-and-forth after that time.

“President Trump is committed to debating Joe Biden regardless of last-minute rule changes from the biased commission in their latest attempt to provide advantage to their favoured candidate,” campaign manager Bill Stepien said.

The Biden campaign did not immediately respond to a request for comment.

More than 30 million Americans have already cast their ballots, limiting Trump’s chances of reframing a contest that national and state opinion polls show him trailing.

Trump repeatedly interrupted Biden during a chaotic and ill-tempered debate on Sept 29, at one point provoking Biden to snap: “Will you shut up, man?”

Earlier on Monday, Trump’s campaign said it was unhappy with the announced set of topics for Thursday’s debate, arguing that it should focus more on foreign policy and asserting that the nonpartisan group was tilted toward Biden.

“I will participate but it’s very unfair that they changed the topics and it’s very unfair that again we have an anchor who’s totally biased,” Trump told reporters aboard Air Force One as he returned to Washington from rallies in Arizona.

Kristen Welker of NBC News, a respected White House reporter, is slated to anchor the debate.

Trump attacks Dr Fauci, press and polls

On the third day of a western campaign swing, Trump was facing intense pressure to turn around his campaign, hoping for the type of last-minute surge that gave him a come-from-behind victory four years ago. But his inconsistent message, another rise in virus cases and his attacks on experts like Dr Anthony Fauci could undermine his final efforts to appeal to voters outside his most loyal base.

“I’m not running scared,” Trump told reporters before taking off for Tucson, Arizona, for his fifth rally in three days. “I think I’m running angry. I’m running happy and I’m running very content ’cause I’ve done a great job.”

His aggressive travel comes as Trump plays defence in states he won four years ago, though the president insisted he was confident as he executed a packed schedule despite the pandemic.

“We’re going to win,” he told campaign staff on a morning conference call from Las Vegas. He went on to acknowledge that he “wouldn’t have told you that maybe two or three weeks ago”, referring to the days when he was hospitalised with Covid-19. But he said he felt better now than at any point in 2016. “We’re in the best shape we’ve ever been,” he said.

Seeking to shore up the morale of his staff amid growing private concerns that he is running out of time to make up lost ground, Trump blasted his government’s own scientific experts as too negative, even as his handling of the pandemic that has killed more than 220,000 Americans remains a central issue to voters.

“People are tired of hearing Fauci and all these idiots,” Trump said of the government’s top infectious disease expert. “Every time he goes on television, there’s always a bomb. But there’s a bigger bomb if you fire him. But Fauci’s a disaster.”

At a rally in Prescott, Arizona, Trump assailed Biden for pledging to heed the advice of scientific experts, saying dismissively that his rival “wants to listen to Dr Fauci.”

The doctor is both respected and popular, and Trump’s rejection of scientific advice on the pandemic has already drawn bipartisan condemnation.

At his rally, Trump also ramped up his attacks on the news media, singling out NBC’s Kristen Welker, the moderator of the next presidential debate, as well as CNN for aggressively covering a pandemic that is now infecting tens of thousands of Americans every day.

Fauci, in an interview with CBS’s “60 Minutes” that aired on Sunday, said he was not surprised that Trump contracted the virus after he held a series of large events with few face coverings.

“I was worried that he was going to get sick when I saw him in a completely precarious situation of crowded, no separation between people, and almost nobody wearing a mask,” Fauci said of the president.

Biden was off the campaign trail on Monday, but his campaign praised Fauci and criticised Trump for “reckless and negligent leadership” that “threatens to put more lives at risk”.

“Trump’s closing message in the final days of the 2020 race is to publicly mock Joe Biden for trusting science and to call Dr Fauci, the leading public health official on Covid-19, a ‘disaster’ and other public health officials ‘idiots’,” the campaign said.